A Visual Way to Play with Docker
You may know that Docker is a lightweight virtualization solution for running multiple virtual units (containers) simultaneously on a single control host. Containers are isolated with kernel control groups (cgroups) and kernel namespaces.
We have had Docker as an integral part of SUSE Linux Enterprise Server for some time already, so let me share some tips on how start using it.
The base Docker packages are included right on the SUSE Linux Enterprise Server media so you can use the regular package management tools to install it and then just go to the docker tool and start using it right away. There are more details in the Docker Quick Start manual, which you could find here.
I want to point out a new thing which we have made available recently in the SUSE Linux Enterprise Server update channels: that’s a Docker YaST module. You could find it in the YaST Control Center easily:
The Docker YaST module’s purpose is to give a simple overview of the available Docker images, running Docker containers and allow for easy manipulation of running containers. This is how it looks like:
You can spawn a container out of an image, optionally selecting mapping of volumes for exposed storage to the container or mapping of network ports.
Once you are done, you will see the container running:
In case you would like to debug your container or make changes, you can easily inject a terminal using the YaST module. What that means is that YaST spawns a selected shell (normally bash) and attaches that to the running container. Then you could work inside of the container like if you would connect to a normal system. When connected, you could check for differences in contents easily.
That outlines the changes between the original image from which the container started and the currently running container. If and when you are okay with the changes, you can commit those changes back to the image, creating a new version with the changes you have made.
All this gives you an easy start with Docker, a comfortable overview of the available images and running containers. You can manipulate the inner contents of the containers, record changes back to the images, etc. For complex tasks you can use the docker tool; the YaST module is meant to simplify onboarding and let you get to know Docker.
The capabilities describe here are what we have released as the initial version, which is made available as an update to SUSE Linux Enterprise Server 12 (just run zypper patch). Stay tuned as we release further updates to the tool itself, as well as add other components related to containers and Docker. And don’t hesitate to let us know about your experience!